Vehicle seat and control method for vehicle seat

Abstract

The objective is to provide a vehicle seat and a control method for the vehicle seat that can suppress the submarine effect for occupants even when the vehicle is in a frontal collision while driving with the seat back tilted backward by a predetermined angle or more. [Solution] A vehicle seat 12 and a control method for the vehicle seat 12 comprising a seat cushion 14 on which an occupant P sits, a seat back 16 configured to be tiltable backward and supporting the back of the occupant P, a lifting mechanism 30 provided on the seat cushion 14 for raising the front part of the seat surface of the seat cushion 14, and a pressing mechanism 20 provided on the seat back 16 for pressing a part of the front surface of the seat back 16 toward the front of the seat, wherein when the backward tilt angle of the seat back 16 is greater than or equal to a predetermined angle and a frontal collision of the vehicle 10 is predicted, the lifting mechanism 30 is activated, followed by the pressing mechanism 20.

Description

Technical Field

[0001] The present invention relates to a vehicle seat and a method for controlling a vehicle seat.

Background Art

[0002] A vehicle occupant protection device that determines that the occurrence of a frontal collision of a vehicle is inevitable and, when the tilt angle of the seat back is a predetermined angle or more, deploys an airbag between the seat back and the upper body of the occupant to raise the upper body of the occupant has been conventionally known (see, for example, Patent Document 1). Further, a vehicle seat structure that tilts the pelvis of an occupant forward by pressing the upper part of the occupant's waist toward the front side of the seat by a pyrotechnic lumbar support during a forward moving collision of a seated occupant has also been conventionally known (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] With the spread of automated driving, driving in a reclined posture (comfortable posture) with the seat back greatly reclined is assumed. However, in such a reclined posture, due to the inertial force during a frontal collision of the vehicle, the component in the direction of the spinal axis of the upper body of the occupant becomes large, and an increase in lumbar load is a concern. Further, in order to suppress an increase in lumbar load, if the back of the seated occupant is pressed forward by an airbag or a lumbar support, there is also a possibility that the seated occupant will move forward, so the effect of suppressing the occurrence of the submarine phenomenon may not be sufficient.

[0005] Therefore, the present invention aims to provide a vehicle seat and a control method for a vehicle seat that can suppress the occurrence of the submarine effect for occupants even when the vehicle is in a frontal collision while the seat back is tilted backward by a predetermined angle or more. [Means for solving the problem]

[0006] To achieve the above objective, a vehicle seat according to a first embodiment of the present invention comprises a seat cushion on which an occupant sits, a seat back that is configured to be tiltable backward and supports the occupant's back, a lifting mechanism provided on the seat cushion for raising the front part of the seat surface of the seat cushion, and a pressing mechanism provided on the seat back for pressing a part of the front surface of the seat back toward the front of the seat, wherein the lifting mechanism is activated and then the pressing mechanism is activated when the backward tilt angle of the seat back is greater than or equal to a predetermined angle and a frontal collision of the vehicle is predicted.

[0007] According to the first embodiment of the invention, the seat cushion on which the occupant sits is provided with a lifting mechanism that raises the front part of the seat surface of the seat cushion. The seat back, which is configured to be tiltable backward and supports the occupant's back, is provided with a pressing mechanism that presses a part of the front of the seat back toward the front of the seat.

[0008] Here, when the seatback is tilted backward at a predetermined angle or greater, and a frontal collision is predicted, the lifting mechanism is activated, followed by the pressing mechanism. In other words, the front part of the seat cushion is raised, and then a portion of the front of the seatback is pressed forward. As a result, the forward movement of the occupant is effectively suppressed. Therefore, even if the vehicle is hit by a frontal collision while driving with the seatback tilted backward at a predetermined angle or greater, the submarining effect on the occupant is suppressed.

[0009] Furthermore, a vehicle seat according to a second embodiment of the present invention is a vehicle seat according to the first embodiment, wherein the lifting mechanism is an electric tilt mechanism, a cushion restraint device, or a seat cushion airbag, and the pressing mechanism is a lumbar support airbag or an electric lumbar support.

[0010] According to the second embodiment of the invention, the lifting mechanism is an electric tilt mechanism, a cushion restraint device, or a seat cushion airbag. Therefore, the front part of the seat cushion surface is effectively raised. Furthermore, the pressing mechanism is a lumbar support airbag or an electric lumbar support. Therefore, a portion of the front of the seat back is effectively pressed toward the front of the seat.

[0011] Furthermore, a third embodiment of the vehicle seat control method according to the present invention is a vehicle seat control method according to the first or second embodiment, comprising: a lifting step in which the lifting mechanism is activated to lift the front part of the seat surface of the seat cushion when the rearward tilt angle of the seat back is greater than or equal to a predetermined angle and a frontal collision of the vehicle is predicted; and a pressing step in which, after the lifting step, the pressing mechanism is activated to press a part of the front of the seat back toward the front of the seat.

[0012] According to the third embodiment of the invention, when the seatback is tilted backward at a predetermined angle or more and a frontal collision of the vehicle is predicted, the front part of the seat cushion is raised (raising step). Then, a part of the front of the seatback is pressed toward the front of the seat (pressing step). As a result, the forward movement of the occupant is effectively suppressed. Therefore, even if the vehicle is driven with the seatback tilted backward at a predetermined angle or more and a frontal collision occurs, the submarine effect for the occupant is suppressed. [Effects of the Invention]

[0013] As described above, according to the present invention, even if the vehicle is involved in a frontal collision while driving with the seat back tilted backward by a predetermined angle or more, the submarine effect for the occupants can be suppressed. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic side view showing the configuration of a vehicle seat according to the first embodiment. [Figure 2] (A) A schematic side view showing the vehicle seat lifting mechanism according to the first embodiment in operation. (B) A schematic side view showing the vehicle seat pressing mechanism according to the first embodiment in operation. [Figure 3] This is a flowchart showing the operation of a vehicle seat according to the first embodiment. [Figure 4] (A) A schematic side view showing the vehicle seat lifting mechanism according to the second embodiment in operation. (B) A schematic side view showing the vehicle seat pressing mechanism according to the second embodiment in operation. [Figure 5] This is a flowchart showing the operation of a vehicle seat according to the second embodiment. [Figure 6] (A) A schematic side view showing the vehicle seat lifting mechanism according to the third embodiment in operation. (B) A schematic side view showing the vehicle seat pressing mechanism according to the first embodiment in operation. [Figure 7] This is a flowchart showing the operation of a vehicle seat according to the third embodiment. [Modes for carrying out the invention]

[0015] The embodiments of the present invention will be described in detail below with reference to the drawings. For the sake of explanation, the arrows UP and FR shown in each figure will indicate the upward direction of the sheet and the forward direction of the sheet, respectively. In the following description, unless otherwise specified, the directions of up, down, front, back, and left and right will refer to the up, down, front, back, and left and right directions on the sheet. The left and right direction is synonymous with the sheet width direction.

[0016] <First Embodiment> First, the first embodiment will be described. As shown in FIG. 1, the vehicle seat 12 according to the first embodiment is provided, for example, as a front seat of a vehicle 10 having an automatic driving mode. The vehicle seat 12 includes a seat cushion 14 on which an occupant sits, and a seat back 16 provided rotatable (tiltable backward and forward) about the seat width direction as an axial direction on the rear side of the seat cushion 14 to support the occupant's back, and a headrest 18 provided vertically movable at the center in the seat width direction at the upper end of the seat back 16 to support the occupant's head.

[0017] In FIG. 1 and the like, a state in which a dummy human figure (anthropomorphic dummy) for a collision test is seated on the seat cushion 14 of the vehicle seat 12 is shown as a model of an occupant (seated person) to be protected. The dummy human figure is, for example, AM50 (50th percentile of American adult males) of a front collision test dummy (Hybrid III). Hereinafter, this dummy human figure will be referred to as "occupant P".

[0018] As shown in FIG. 1, when the vehicle 10 is in the automatic driving mode, the occupant P may take a reclining posture in which the seat back 16 is tilted backward by a predetermined angle θ or more with respect to the vertical direction. In FIG. 1, as an example, a state in which the seat back 16 is tilted backward by 45 degrees with respect to the vertical direction is shown, and the predetermined angle θ referred to here is, for example, 45 degrees.

[0019] Note that the tilt angle of the seat back 16 is configured to be detected by a detection sensor 24 or the like. Further, the vehicle 10 is provided with a prediction sensor 26 or the like for predicting a front collision at a predetermined position. Further, the vehicle 10 is provided with a control device 28 electrically connected to the detection sensor 24 and the prediction sensor 26 at a predetermined position.

[0020] As shown in Figure 2(B), the seat back 16 is provided with a lumbar support airbag 22 that presses forward against a portion of the front surface 16A of the seat back 16 (specifically, the surface of the part facing the occupant P's waist), and an inflator (not shown) that sprays gas into the lumbar support airbag 22. The lumbar support airbag 22 and the inflator that sprays gas into the lumbar support airbag 22 constitute a pressing mechanism 20, and the inflator is also electrically connected to the control device 28 (see Figure 1).

[0021] The pressing mechanism 20 is not limited to a configuration consisting of a lumbar support airbag 22 and an inflator that injects gas into the lumbar support airbag 22. Although not shown in the figures, it may also be an electric lumbar support that includes, for example, a plate that moves forward by the drive of an electric motor and presses a part of the front surface 16A of the seat back 16 forward. In this case, the electric motor is electrically connected to the control device 28.

[0022] Furthermore, as shown in Figures 2(A) and 2(B), the seat cushion 14 is provided with an electric tilt mechanism 32, which serves as a lifting mechanism 30 for raising the front part of the seat surface 14A of the seat cushion 14. The electric tilt mechanism 32 is a known mechanism and is electrically connected to the control device 28.

[0023] The control device 28 is configured to first activate the electric tilt mechanism 32 when the rearward tilt angle of the seat back 16 is greater than or equal to a predetermined angle θ and a frontal collision of the vehicle 10 is predicted. Then, after that (with a predetermined time delay), the control device 28 is configured to activate an inflator that injects gas into the lumbar support airbag 22, thereby inflating the lumbar support airbag 22.

[0024] In the vehicle seat 12 according to the first embodiment, which has the configuration described above, its operation (control method) will now be explained based on the flowchart shown in Figure 3.

[0025] As shown in Figure 3, first the reclining angle of the seat back 16 is detected by the detection sensor 24 (step S11). When the reclining angle is less than a predetermined angle θ (for example, θ = 45 degrees), the lifting mechanism 30 and the pressing mechanism 20 do not operate. When the reclining angle is greater than or equal to the predetermined angle θ, it is then determined whether or not a frontal collision of the vehicle 10 is predicted (step S12). If a frontal collision of the vehicle 10 is not predicted, the lifting mechanism 30 and the pressing mechanism 20 do not operate.

[0026] If a frontal collision of vehicle 10 is predicted, first, as shown in Figure 2(A), the control device 28 activates the electric tilt mechanism 32 as the lifting mechanism 30 to raise the front of the seat cushion 14 (lifting process: step S13). Then, as shown in Figure 2(B), the control device 28 activates the pressing mechanism 20. That is, the control device 28 activates the inflator that injects gas into the lumbar support airbag 22, inflating the lumbar support airbag 22 (pressing process: step S14).

[0027] Thus, when the seatback 16 is tilted backward at a predetermined angle θ or greater, and a frontal collision of the vehicle 10 is predicted, the lifting mechanism 30 is activated, followed by the pressing mechanism 20. In other words, the front part of the seat surface 14A of the seat cushion 14 is raised, and then a part of the front surface 16A of the seatback 16 is pressed forward. As a result, the forward movement of the occupant P is effectively suppressed. Therefore, even if the vehicle 10 is involved in a frontal collision while driving with the seatback 16 tilted backward at a predetermined angle θ or greater, the submarining effect on the occupant P can be effectively suppressed.

[0028] Furthermore, since the lifting mechanism 30 is an electric tilt mechanism 32, the front part of the seat surface 14A of the seat cushion 14 can be effectively raised. Also, since the pressing mechanism 20 is a lumbar support airbag 22, a part of the front surface 16A of the seat back 16 can be effectively pressed forward. The same applies when the pressing mechanism 20 is an electric lumbar support.

[0029] <Second Embodiment> Next, a second embodiment will be described. Note that parts equivalent to those in the first embodiment are denoted by the same reference numerals, and detailed descriptions will be omitted as appropriate.

[0030] As shown in Figures 4(A) and 4(B), this second embodiment differs from the first embodiment in that the lifting mechanism 30 is composed of a cushion restraint device (hereinafter referred to as "CRD34"). The CRD34 is built into the front part of the seat cushion 14.

[0031] The CRD34 comprises a main body portion 34A extending in the sheet width direction, support rods 34B with one end rotatably provided at both ends of the main body portion 34A in the sheet width direction, and a pivot shaft 34C provided axially in the sheet width direction, with the other end of the support rod 34B fixed to both ends.

[0032] The main body 34A is made of, for example, resin and is formed in a substantially elliptical shape with a predetermined thickness when viewed from the side. The pivot shaft 34C is rotatably supported at the front end of a seat cushion frame (not shown) located inside the seat cushion 14. An electric motor (not shown) is connected to the pivot shaft 34C via a gearbox (not shown), and the electric motor is electrically connected to a control device 28.

[0033] Therefore, the control device 28 first activates the electric motor when the rearward tilt angle of the seat back 16 is greater than or equal to a predetermined angle θ and a frontal collision of the vehicle 10 is predicted. That is, the control device 28 drives the electric motor to rotate the pivot shaft 34C in the counterclockwise direction shown in the figure, raising the main body 34A of the CRD 34. Then, the control device 28 activates an inflator that injects gas into the lumbar support airbag 22, thereby inflating the lumbar support airbag 22.

[0034] In the vehicle seat 12 according to the second embodiment, which has the configuration described above, its operation (control method) will now be explained based on the flowchart shown in Figure 5. Note that explanations of operations equivalent to those of the first embodiment will be omitted as appropriate.

[0035] As shown in Figure 5, first the reclining angle of the seat back 16 is detected by the detection sensor 24 (step S21). When the reclining angle is less than a predetermined angle θ (for example, θ = 45 degrees), the lifting mechanism 30 and the pressing mechanism 20 do not operate. When the reclining angle is greater than or equal to the predetermined angle θ, it is then determined whether or not a frontal collision of the vehicle 10 is predicted (step S22). If a frontal collision of the vehicle 10 is not predicted, the lifting mechanism 30 and the pressing mechanism 20 do not operate.

[0036] If a frontal collision of vehicle 10 is predicted, first, as shown in Figure 4(A), the control device 28 activates the CRD 34 as a lifting mechanism 30 to raise the front part of the seat cushion 14 (lifting process: step S23). Then, as shown in Figure 4(B), the control device 28 activates the pressing mechanism 20. That is, the control device 28 activates an inflator that injects gas into the lumbar support airbag 22, inflating the lumbar support airbag 22 (pressing process: step S24).

[0037] Thus, in the second embodiment as in the first embodiment, when the rearward tilt angle of the seat back 16 is greater than or equal to a predetermined angle θ and a frontal collision of the vehicle 10 is predicted, the lifting mechanism 30 is activated, followed by the pressing mechanism 20. In other words, the front part of the seat surface 14A of the seat cushion 14 is raised, and then a part of the front surface 16A of the seat back 16 is pressed forward.

[0038] Therefore, the forward movement of the occupant P is effectively suppressed, and even if the vehicle 10 is involved in a frontal collision while driving with the seat back 16 tilted backward by a predetermined angle θ or more, the submarining effect on the occupant P can be effectively suppressed. In addition, since the lifting mechanism 30 is a CRD 34, the front part of the seat surface 14A of the seat cushion 14 can be effectively raised.

[0039] <Third Embodiment> Finally, a third embodiment will be described. Note that parts equivalent to those in the first embodiment are denoted by the same reference numerals, and detailed descriptions will be omitted as appropriate.

[0040] As shown in Figures 6(A) and 6(B), this third embodiment differs from the first embodiment in that the lifting mechanism 30 consists of a seat cushion airbag 36 and an inflator (not shown) that ejects gas into the seat cushion airbag 36.

[0041] The seat cushion airbag 36 is built into the front of the seat cushion 14, and the inflator that injects gas into the seat cushion airbag 36 is located inside or outside the seat cushion 14. The inflator that injects gas into the seat cushion airbag 36 is electrically connected to the control device 28.

[0042] Therefore, when the rearward tilt angle of the seat back 16 is greater than or equal to a predetermined angle θ and a frontal collision of the vehicle 10 is predicted, the control device 28 first activates an inflator that injects gas into the seat cushion airbag 36, thereby inflating the seat cushion airbag 36. Then, the control device 28 activates an inflator that injects gas into the lumbar support airbag 22, thereby inflating the lumbar support airbag 22.

[0043] In the vehicle seat 12 according to the third embodiment, which has the configuration described above, its operation (control method) will now be explained based on the flowchart shown in Figure 7. Note that explanations of operations equivalent to those of the first embodiment will be omitted as appropriate.

[0044] As shown in Figure 7, first the reclining angle of the seat back 16 is detected by the detection sensor 24 (step S31). When the reclining angle is less than a predetermined angle θ (for example, θ = 45 degrees), the lifting mechanism 30 and the pressing mechanism 20 do not operate. When the reclining angle is greater than or equal to the predetermined angle θ, it is then determined whether or not a frontal collision of the vehicle 10 is predicted (step S32). If a frontal collision of the vehicle 10 is not predicted, the lifting mechanism 30 and the pressing mechanism 20 do not operate.

[0045] If a frontal collision of vehicle 10 is predicted, first, as shown in Figure 6(A), the control device 28 activates an inflator that injects gas into the seat cushion airbag 36, which acts as a lifting mechanism 30, thereby inflating the seat cushion airbag 36. As a result, the front part of the seat cushion 14 is raised (lifting process: step S33).

[0046] Then, as shown in Figure 6(B), the control device 28 activates the pressing mechanism 20. That is, the control device 28 activates the inflator that injects gas into the lumbar support airbag 22, thereby inflating the lumbar support airbag 22 (pressing process: step S34).

[0047] Thus, in the third embodiment as in the first embodiment, when the rearward tilt angle of the seat back 16 is greater than or equal to a predetermined angle θ and a frontal collision of the vehicle 10 is predicted, the lifting mechanism 30 is activated, followed by the pressing mechanism 20. In other words, the front part of the seat surface 14A of the seat cushion 14 is raised, and then a part of the front surface 16A of the seat back 16 is pressed forward.

[0048] Therefore, the forward movement of the occupant P is effectively suppressed, and even if the vehicle 10 is involved in a frontal collision while driving with the seat back 16 tilted backward by a predetermined angle θ or more, the submarining effect on the occupant P can be effectively suppressed. In addition, since the lifting mechanism 30 is a seat cushion airbag 36, the front part of the seat surface 14A of the seat cushion 14 can be effectively raised.

[0049] The vehicle seat 12 and its control method according to this embodiment have been described above with reference to the drawings. However, the vehicle seat 12 and its control method according to this embodiment are not limited to those shown, and can be modified as appropriate without departing from the spirit of the present invention. For example, the pressing mechanism 20 and the lifting mechanism 30 are not limited to those of the embodiments described above. Furthermore, the vehicle seat 12 according to this embodiment may be installed as a rear seat of a vehicle 10, or as a front or rear seat of a vehicle that does not have an automatic driving mode. [Explanation of Symbols]

[0050] 10 vehicles 12 Vehicle seats 14 Seat Cushions 16 Seatback 20 Pressing mechanism 22 Lumbar support airbag 30 Lifting mechanism 32 Electric tilt mechanism 34 CRD (Cushion Restraint Device) 36 Seat cushion airbags P Crew

Claims

1. The seat cushion on which the occupants sit, A seat back that is configured to be tiltable backward and supports the back of the occupant, The aforementioned seat cushion is provided with a lifting mechanism that raises the front part of the seat surface of the seat cushion, A pressing mechanism provided on the seat back presses a portion of the front surface of the seat back toward the front of the seat, Equipped with, A vehicle seat configured such that when the rearward tilt angle of the seat back is greater than or equal to a predetermined angle, and a frontal collision of the vehicle is predicted, the lifting mechanism is activated, followed by the pressing mechanism.

2. The aforementioned lifting mechanism is an electric tilt mechanism, a cushion restraint device, or a seat cushion airbag. The vehicle seat according to claim 1, wherein the pressing mechanism is a lumbar support airbag or an electric lumbar support.

3. A method for controlling a vehicle seat according to claim 1 or claim 2, When the rearward tilt angle of the seat back is greater than or equal to a predetermined angle and a frontal collision of the vehicle is predicted, the lifting mechanism is activated to raise the front part of the seat cushion surface, After the lifting step, the pressing step involves activating the pressing mechanism to press a portion of the front surface of the seat back toward the front of the seat, A method for controlling a vehicle seat having the following features.

Images